Updated AT91RM9200 support

[Warner Losh]

I've just committed support necessary to get the AT91RM9200 booting
over a NFS root.  Many thanks to cognet@ for his help and support.

Warner

>e 0x20000000
KDB: debugger backends: ddb
KDB: current backend: ddb
Copyright (c) 1992-2006 The FreeBSD Project.
Copyright (c) 1979, 1980, 1983, 1986, 1988, 1989, 1991, 1992, 1993,
1994
        The Regents of the University of California. All rights
reserved.
FreeBSD 7.0-CURRENT #325: Fri Mar 17 16:48:12 MST 2006
    imp at Speedy.timing.com:/r/stg/imp/p4/arm/src/sys/arm/compile/KB920X
CPU: ARM920T rev 0 (ARM9TDMI core)
  DC enabled IC enabled WB enabled LABT
  16KB/32B 64-way Instruction cache
  16KB/32B 64-way write-back-locking-A Data cache
atmelarm0: <AT91RM9200 device bus> on motherboard
at91_st0: <ST> mem 0xfffffd00:0x100 irq 1 on atmelarm0
at91_pio0: <PIO> mem 0xfffff400:0x200 irq 1 on atmelarm0
at91_pio0: [FAST]
at91_pio1: <PIO> mem 0xfffff600:0x200 irq 1 on atmelarm0
at91_pio1: [FAST]
at91_pio2: <PIO> mem 0xfffff800:0x200 irq 1 on atmelarm0
at91_pio2: [FAST]
at91_pio3: <PIO> mem 0xfffffa00:0x200 irq 1 on atmelarm0
at91_pio3: [FAST]
at91_pmc0: <PMC> mem 0xfffffc00:0x100 irq 1 on atmelarm0
at91_pmc0: main clock: 10000000 Hz PLLA: 180 MHz CPU: 180 MHz main 60 MHz
at91_twi0: <TWI> mem 0xfffb8000:0x4000 irq 12 on atmelarm0
ate0: <EMAC> mem 0xfffbc000:0x4000 irq 24 on atmelarm0
miibus0: <MII bus> on ate0
ukphy0: <Generic IEEE 802.3u media interface> on miibus0
ukphy0:  10baseT, 10baseT-FDX, 100baseTX, 100baseTX-FDX, auto
ate0: Ethernet address: 42:53:44:00:00:01
uart0: <DBGU> mem 0xfffff200:0x200 irq 1 on atmelarm0
uart0: [FAST]
uart0: console (115200,n,8,1)
uart1: <USART0> mem 0xfffc0000:0x4000 irq 6 on atmelarm0
uart1: [FAST]
uart2: <USART1> mem 0xfffc4000:0x4000 irq 7 on atmelarm0
uart2: [FAST]
uart3: <USART2> mem 0xfffc8000:0x4000 irq 8 on atmelarm0
uart3: [FAST]
uart4: <USART3> mem 0xfffcc000:0x4000 irq 9 on atmelarm0
uart4: [FAST]
at91_ssc0: <SSC> mem 0xfffd0000:0x4000 irq 14 on atmelarm0
at91_ssc1: <SSC> mem 0xfffd4000:0x4000 irq 15 on atmelarm0
at91_ssc2: <SSC> mem 0xfffd8000:0x4000 irq 16 on atmelarm0
at91_spi0: <SPI> mem 0xfffe0000:0x4000 irq 13 on atmelarm0
Cannot get 100 Hz clock; using 128Hz
at91_st0: [FAST]
Timecounter "AT91RM9200 timer" frequency 32768 Hz quality 0
Timecounters tick every 7.812 msec
Sending DHCP Discover packet from interface ate0 (42:53:44:00:00:01)
ate0: link state changed to DOWN
ate0: link state changed to UP
Received DHCP Offer packet on ate0 from x.y.z.218 (accepted) (no root path)
Received DHCP Offer packet on ate0 from x.y.z.219 (ignored) (no root path)
Sending DHCP Request packet from interface ate0 (42:53:44:00:00:01)
Received DHCP Ack packet on ate0 from x.y.z.218 (accepted) (got root path)
ate0 at x.y.z.194 server x.y.z.218 boot file kernel.bin
subnet mask 255.255.255.128 router x.y.z.129 rootfs
x.y.z.207:/arm-nfsroot 
Adjusted interface ate0
Trying to mount root from nfs:
NFS ROOT: x.y.z.207:/arm-nfsroot
warning: no time-of-day clock registered, system time will not be set accurately
warning: no time-of-day clock registered, system time will not be set accurately
Enter full pathname of shell or RETURN for /bin/sh: 
# ls
.snap   boot    etc     libexec proc    root    sys     usr
bin     dev     lib     mnt     rescue  sbin    tmp     var
# uname -a
FreeBSD  7.0-CURRENT FreeBSD 7.0-CURRENT #325: Fri Mar 17 16:48:12 MST 2006
imp at Speedy.timing.com:/r/stg/imp/p4/arm/src/sys/arm/compile/KB920X arm
#